Python/dynload_shlib.c

   1
   2 /* Support for dynamic loading of extension modules */
   3
   4 #include "Python.h"
   5 #include "importdl.h"
   6
   7 #include <sys/types.h>
   8 #include <sys/stat.h>
   9
  10 #if defined(__NetBSD__)
  11 #include <sys/param.h>
  12 #if (NetBSD < 199712)
  13 #include <nlist.h>
  14 #include <link.h>
  15 #define dlerror() "error in dynamic linking"
  16 #endif
  17 #endif /* NetBSD */
  18
  19 #ifdef HAVE_DLFCN_H
  20 #include <dlfcn.h>
  21 #else
  22 #if defined(PYOS_OS2) && defined(PYCC_GCC)
  23 #include "dlfcn.h"
  24 #endif
  25 #endif
  26
  27 #if (defined(__OpenBSD__) || defined(__NetBSD__)) && !defined(__ELF__)
  28 #define LEAD_UNDERSCORE "_"
  29 #else
  30 #define LEAD_UNDERSCORE ""
  31 #endif
  32
  33
  34 const struct filedescr _PyImport_DynLoadFiletab[] = {
  35 #ifdef __CYGWIN__
  36         {".dll", "rb", C_EXTENSION},
  37         {"module.dll", "rb", C_EXTENSION},
  38 #else
  39 #if defined(PYOS_OS2) && defined(PYCC_GCC)
  40         {".pyd", "rb", C_EXTENSION},
  41         {".dll", "rb", C_EXTENSION},
  42 #else
  43         {".so", "rb", C_EXTENSION},
  44         {"module.so", "rb", C_EXTENSION},
  45 #endif
  46 #endif
  47         {0, 0}
  48 };
  49
  50 static struct {
  51         dev_t dev;
  52         ino_t ino;
  53         void *handle;
  54 } handles[128];
  55 static int nhandles = 0;
  56
  57
  58 dl_funcptr _PyImport_GetDynLoadFunc(const char *fqname, const char *shortname,
  59                                     const char *pathname, FILE *fp)
  60 {
  61         dl_funcptr p;
  62         void *handle;
  63         char funcname[258];
  64         char pathbuf[260];
  65         int dlopenflags=0;
  66
  67         if (strchr(pathname, '/') == NULL) {
  68                 /* Prefix bare filename with "./" */
  69                 PyOS_snprintf(pathbuf, sizeof(pathbuf), "./%-.255s", pathname);
  70                 pathname = pathbuf;
  71         }
  72
  73         PyOS_snprintf(funcname, sizeof(funcname),
  74                       LEAD_UNDERSCORE "init%.200s", shortname);
  75
  76         if (fp != NULL) {
  77                 int i;
  78                 struct stat statb;
  79                 fstat(fileno(fp), &statb);
  80                 for (i = 0; i < nhandles; i++) {
  81                         if (statb.st_dev == handles[i].dev &&
  82                             statb.st_ino == handles[i].ino) {
  83                                 p = (dl_funcptr) dlsym(handles[i].handle,
  84                                                        funcname);
  85                                 return p;
  86                         }
  87                 }
  88                 if (nhandles < 128) {
  89                         handles[nhandles].dev = statb.st_dev;
  90                         handles[nhandles].ino = statb.st_ino;
  91                 }
  92         }
  93
  94 #if !(defined(PYOS_OS2) && defined(PYCC_GCC))
  95         dlopenflags = PyThreadState_Get()->interp->dlopenflags;
  96 #endif
  97
  98         if (Py_VerboseFlag)
  99                 printf("dlopen(\"%s\", %x);\n", pathname, dlopenflags);
 100
 101         handle = dlopen(pathname, dlopenflags);
 102
 103         if (handle == NULL) {
 104                 PyErr_SetString(PyExc_ImportError, dlerror());
 105                 return NULL;
 106         }
 107         if (fp != NULL && nhandles < 128)
 108                 handles[nhandles++].handle = handle;
 109         p = (dl_funcptr) dlsym(handle, funcname);
 110         return p;
 111 }